No difference in flashing stock 4.0.4, except you get new radio files, which you can flash on your own anyway.
Regarding the wipe, there's no need to wipe battery stats, as it has no bearing on installation issues. I'm still on the kernal that comes with it. I, too, am a LeanKernal lover, but I'm testing this one out. It seems pretty good, thus far.
Regarding the other wipings, yes, cache, data, dalvik and system. Then flash b40, then immediately flash gapps. You can allow google to re-d/l and install your apps automatically, then use TiBu to refresh important data, like passwords and the like, if you reaaaaaally want a clean install. For example, instead of re-doing passwords and settings on stuff like words with friends and pandora and stuff, I'll (if I want a really clean install) simply restore data only onto the new install.
TMI, here, I think. Let us know if you need any other help.
Steven